The liquid crystal display (LCD) is a passive light emitting device, a backlight unit (BLU) is required to provide a light source to the liquid crystal display to enable it to display images. At present, the backlight technologies mainly used by the liquid crystal display include: a cold cathode fluorescent lamp (CCFL) and a light emitting diode (LED). Since the LED backlight has lots of advantages of high luminance, high color purity, long lifetime, good reliability and no mercury pollution etc., it occupies an increasingly large proportion in the use of the backlight.
The LED backlight liquid crystal display can be classified into a straight down type and a side entry type according to the position of the LED backlight. FIG. 1 shows a structural schematic view of a side entry type backlight display device of the prior art. As shown in FIG. 1, a backlight unit arranged at a side of a display panel 10 comprises a light guide plate 11, an LED strip light 12 located at the side of the light guide plate 11, and a reflector 13 located at the back of the light guide plate 11. After the light emitted by the LED strip light 12 is incident into the light guide plate 11, via reflection by the reflector 13 and scattering by the light guide plate 11, the light is propagated to the light exit side of the display panel 10, so as to achieve the aim of providing a light source to the liquid crystal display to enable it to display images.
In the side entry type liquid crystal display of the prior art, in order to increase the utilization rate of the light emitted by the LED strip light 12, the thickness H of the light guide plate 11 is generally slightly greater than the width h of the LED strip light 12 in the design and fabrication process. However, in this way, the thickness of the light guide plate 11 will be increased, thereby enabling the thickness of the backlight unit to be enlarged, which does not conform to the design trend of ultra-thinness of the display.